The thin line: Paralympic classification causes controversy

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Photos:Classifiying Paralympic ability

Classifying disability – Due to the Paralympics' classification rules, South Africa's double amputee "Blade Runner" Oscar Pistorius can line up against runners with only one prosthetic leg.

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Photos:Classifiying Paralympic ability

Defying the odds – Chinese swimmer Zheng Tao has no arms, but that didn't stop him winning gold against competitors more physically abled.

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Photos:Classifiying Paralympic ability

Level playing field? – Britain's gold medalist Jonathan Fox looked "more able" outside the pool than his swimming rivals, according to former Canadian Paralympic middle-distance runner David Howe, who is now an academic.

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Controversial changes – Paralympic swimmer Mallory Weggemann, along with U.S. teammate Victoria Arlen, have both battled the International Paralympic Committee after having their classifications changed.

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Photos:Classifiying Paralympic ability

Breaking it down – Athletes are placed in one of six main disability groups: those with spinal injuries, cerebral palsy, amputees, the blind or visually impaired, intellectual disabilities and those whose disabilities fall outside of those categories, like those born with dwarfism or multiple sclerosis.

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From 1 to 10 – Each of the Paralympics' 20 sports are divided between the different classifications and given a number that denotes the severity of the disability -- 1 being the most severe, 10 the least.

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'Look to the potential' – The IPC has complicated things further by trying to slim down the number of medals and disciplines and look beyond the disability as the defining factor in classification. Instead, it says, look to the potential of the athlete.

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Story highlights

The issue of disability classification at the Paralympics has caused controversy

Each athlete is placed in events according to disability and ability

Two U.S. swimmers battle ruling body after classifications are changed

IPC trying to slim down the number of medals and disciplines at the Games

Every athlete competing at the London 2012 Paralympic Games has an incredible story to tell, of how they overcame tragedy or a disability they had been born with to be considered the best in the world in their chosen discipline.

But for some the final, bureaucratic hurdle can prove a step too far.

On Thursday it was revealed that the American swimming team's great hope of a gold medal in the pool -- 17-year-old Victoria Arlen -- had been denied a classification to compete.

Arlen had dreamed of making the London 2012 able-bodied swimming team until a neurological disease put her in a coma for two years. When she woke up she was paralyzed in both legs. Yet Arlen continued to swim and this year broke two world records. But after the International Paralympic Committee (IPC) reviewed her case, Arlen was told she could not compete.

It had been decided that Arlen's disability wasn't severe enough. It appeared that she had lost out because of the complex system of disability classification, an essential tool for the Paralympic movement.

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And she's not the only one to suffer. Fellow U.S. swimmer Mallory Weggemann, who lost the use of her legs after a routine epidural injection went wrong, declared she had "lost faith" in the system when her classification was changed just before the start of London 2012.

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"I have trained the past four and a half years for these Games and within less then 24 hours before my first race was supposed to start it all changed, everything I had prepared myself for these past four years changed right there and then," said the 23-year-old, who had been hoping to compete for nine golds but can now only go for seven.

Complex

Such is the myriad of different disabilities, and severity of disabilities, each athlete has to be evaluated and placed into a category to compete alongside others of the same potential.

Athletes are placed in one of six main disability groups: those with spinal injuries, cerebral palsy, amputees, the blind or visually impaired, intellectual disabilities and those whose disabilities fall outside of those categories, like those born with dwarfism or multiple sclerosis.

Each of the Paralympics' 20 sports are divided between the different classifications and given a number that denotes the severity of the disability -- 1 being the most severe, 10 the least.

Paralympics 2012: The best photos – Gold medalist Oscar Pistorius of South Africa throws a bouquet of flowers on the podium during the medal ceremony for the men's 400-meter T44 final Saturday, September 8, at the 2012 Paralympic Games.

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Paralympics 2012: The best photos – The United States' Joseph Chambers reaches for the ball during Saturday's bronze medal wheelchair basketball game between United States and Great Britain.

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Paralympics 2012: The best photos – China's Yang Ge serves against Poland's Sebastian Powrozniak during the men's team table tennis Class 9-10 final on Saturday.

Paralympics 2012: The best photos – Australian Madison De Rozario looks on prior to the women's 400-meter T53 final on Saturday.

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Paralympics 2012: The best photos – Aniek Van Koot, left, and Jiske Griffioen of the Netherlands in action against Marjolein Buis and Esther Vergeer, also of the of Netherlands, in the women's doubles gold medal match.

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Paralympics 2012: The best photos – Richard Browne of the United States competes in the men's high jump F46 final on Saturday.

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Paralympics 2012: The best photos – South Africa's Oscar Pistorius, also known as the "Blade Runner," crosses the line to win gold in the men's 400-meter T44 final. Pistorius also competed in the London Olympics.

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Paralympics 2012: The best photos – No. 13 Derrick Helton of the United States attempts to get the ball from No. 13 Jared Funk of Canada during Saturday's mixed wheelchair rugby semifinal match between the U.S. and Canada.

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Paralympics 2012: The best photos – Thailand's Pattaya Tadtong, right, celebrates beating Britain's David Smith, left, in the final of the boccia individual BC1 competition on Saturday.

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Paralympics 2012: The best photos – The sun sets as Shingo Kunieda of Japan, front left, plays against Stephane Houdet of France in the men's wheelchair tennis gold medal match on Saturday.

Paralympics 2012: The best photos – Sophie Pascoe of New Zealand prepares to compete Saturday in the women's 100-meter breaststroke SB9 final.

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Paralympics 2012: The best photos – From left to right: Canada's Brent Lakatos passes over to teammate Alexandre Dupont and Mexico's Juan Pablo Cervantes Garcia to Jaime Ramirez Valencia in the men's 4x400-meter relay on Saturday.

Paralympics 2012: The best photos – South Korea's Choi Ye-Jin watches her shot in the gold medal final of the boccia mixed individual BC3 competition against South Korea's Jeong Ho-won on Saturday.

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Paralympics 2012: The best photos – Simon Wilson, left, of Great Britain competes against Tang Tat Wong of Hong Kong during the men's open wheelchair fencing quarter-final match on Saturday.

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Paralympics 2012: The best photos – Jack Bridge of Great Britain celebrates after his men's 100-meter breaststroke on Saturday.

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Paralympics 2012: The best photos – Tim Prendergast of New Zealand competes in the men's 800-meter T13 final on Saturday.

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Paralympics 2012: The best photos – A volunteer holds a ball during the soccer match between Great Britain and Turkey on Saturday.

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Paralympics 2012: The best photos – Abdellatif Baka of Algeria reacts after winning the gold during the men's 800-meter T13 final on Saturday.

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Paralympics 2012: The best photos – Audrey Le Morvan of France prepares to serve against Poland in the women's team table tennis bronze medal match on Saturday.

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Paralympics 2012: The best photos – Toshihiro Takada of Japan competes in the men's 200-meter T52 heats on Saturday.

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Paralympics 2012: The best photos – Neda Bahi of Tunisia crosses the line to win gold ahead of silver medalist Viktoriya Kravchenko of Ukraine, No. 1389, and bronze medalist Evgeniya Trushnikova of Russia, No. 1337, in the women's 400-meter T37 final on Saturday.

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Paralympics 2012: The best photos – Faridul Bin Masri of Malaysia competes in the men's javelin throw final on Saturday.

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Paralympics 2012: The best photos – Robbi Weldon and Lynne Bessette of Canada ride in the women's cycling road race on Saturday.

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Paralympics 2012: The best photos – Doniyor Saliev of Uzbekistan competes in the men's triple jump F12 final on Saturday.

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Paralympics 2012: The best photos – A picture shows the shadow of competitors as they compete in the men's javelin throw F42 final on Friday, September 7.

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Paralympics 2012: The best photos – Netherlands' Esther Vergeer keeps a spare ball in the spokes of her wheelchair as she plays Netherlands' Aniek Van Koot in the women's singles wheelchair tennis final on Friday.

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Paralympics 2012: The best photos – Thomas Schmidberger of Germany competes in the final of the Men's Team Table Tennis - Class 3 against China on Friday.

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Paralympics 2012: The best photos – A detailed view of wheelchairs during the men's pool phase Group A rugby match between Great Britain and Japan on Friday.

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Paralympics 2012: The best photos – A shadow of Lucy Shuker serving with partner (out of frame) Jordanne Whiley of Great Britain to Sakhorn Khanthasit and Ratana Techamaneewat of Thailand in the women's doubles bronze medal match for wheelchair tennis on Friday.

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Paralympics 2012: The best photos – Great Britain fans cheer on their athletes on Friday.

Paralympics 2012: The best photos – Kieran Tscherniawsky of Great Britain competes in the men's discus throw F32/33/34 final on Friday.

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Paralympics 2012: The best photos – South Africa's Johanna Pretorius competes in the women's long jump F13 final on Friday.

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Paralympics 2012: The best photos – Valerie Grand-Maison of Canada celebrates after winning gold in the women's 200m individual medley - SM13 final on Friday.

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Paralympics 2012: The best photos – Cristian Valenzuela of Chile and guide Cristopher Guajardo react as they win gold in the men's 5000m T11 final on Friday.

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Paralympics 2012: The best photos – Sarah Rung, right, of Norway touches the wall ahead of Teresa Perales, left, of Spain to win gold in the women's 50m butterfly - S5 final on Friday.

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Paralympics 2012: The best photos – Silver medallist Dmitrii Kokarev of Russia, gold medallist Yang Yang of China and bronze medallist Arisdteidis Makrodimitris of Greece pose on the podium during the medal ceremony for the men's 50m freestyle - S2 final on Friday.

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Paralympics 2012: The best photos – A medal bearer carries a medal and flowers on Friday.

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Paralympics 2012: The best photos – The team of Finland celebrates after winning their men's team goalball gold medal match against Brazil on Friday.

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Paralympics 2012: The best photos – Leomon Moreno Da Silva of Brazil and teammate Jose Roberto Ferreira De Oliveira block the ball during their men's team goalball gold-medal match against Finland on Friday.

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Paralympics 2012: The best photos – Switzerland's Marcel Hug competes in the men's 400m - T54 final on Friday.

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Paralympics 2012: The best photos – Rudy Garcia-Tolson, center, of the United States competes in the men's 100-meter T42 heats at the London 2012 Paralympic Gameson Friday.

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Paralympics 2012: The best photos – Oksana Zubkovska of Ukraine competes in the women's long jump F11/12 final on Friday.

Paralympics 2012: The best photos – China's Li Duan competes in the men's triple jump F11 final on Thursday.

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Paralympics 2012: The best photos – Yoojeong Lee of the Republic of Korea, right, shoots during the women's R8-50m rifle 3 positions-SH1 final on Thursday.

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Paralympics 2012: The best photos – Britain's Sarah Storey, left, bites her gold medal as her nephew Gethin Crayford holds it on the podium after she won the women's individual C4-5 road race cycling final on Thursday.

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Paralympics 2012: The best photos – Fiona Southorn of New Zealand in action in the women's individual C 4-5 road race on Thursday.

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Paralympics 2012: The best photos – Michelle Alonso Morales of Spain celebrates after winning gold in the women's 100m breaststroke - SB14 final on Thursday.

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Paralympics 2012: The best photos – Argentina's captain Silvio Velo runs past Brazilian players to shoot at goal during the men's 5-a-side football semi-final match between Argentina and Brazil on Thursday.

Paralympics 2012: The best photos – Jorge Benjamin Gonzalez Sauceda of Mexico celebrates winning bronze in the men's 400m - T12 final on Thursday, September 6.

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Paralympics 2012: The best photos – Brazil's Jeferson da Conceicao Goncalves is seen during the game against Argentina during the men's 5-a-side football semi-final match between Argentina and Brazil on Thursday.

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Paralympics 2012: The best photos – Samantha Cameron and David Cameron watch Great Britain play France during a Paralympic wheelchair rugby match on Thursday.

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Paralympics 2012: The best photos – Hannah Cockroft of Great Britain wins gold in the women's 200m - T34 final on Thursday.

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Paralympics 2012: The best photos – Gold medalist Hannah Cockroft of Great Britain is congratulated by Melissa Nicholls of Great Britain on Thursday.

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Paralympics 2012: The best photos – Silver medallist Edenia Garcia of Brazil poses on the podium during the medal ceremony for the women's 50m backstroke - S4 final on Thursday.

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Paralympics 2012: The best photos – Jonathan De Souza Santos of Brazil competes in the men's shot put - F40 on Thursday.

Paralympics 2012: The best photos – Jiri Jezek of the Czech Republic leads the group during the men's individual C4-5 road race in Longfield, England, on Thursday.

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Paralympics 2012: The best photos – Amy Conroy of Great Britain takes a shot during the women's classification crossover wheelchair basketball match between Great Britain and China on Thursday.

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Paralympics 2012: The best photos – Marieke Vervoort of Belgium reacts as she wins gold in the women's 100-meter T52 final on Day 7 of the London 2012 Paralympics on Thursday.

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Paralympics 2012: The best photos – Members of the Brazilian team huddle after the men's 4x100-meter relay T42/T46 final on Thursday.

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Paralympics 2012: The best photos – South Africa's Oscar Pistorius lunges toward the finish line ahead of Brazil's Alan Oliveira as he anchors his team to win the men's 4x100-meter relay T42-46 final and set a new world record on Thursday.

Paralympics 2012: The best photos – Czech Republic's Jiri Jezek reacts after winning the gold medal in the men's individual C4 time trial cycling final on Wednesday, September 5, at the London 2012 Paralympics in London.

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Paralympics 2012: The best photos – Alessandro Zanardi of Italy celebrates winning the men's individual H4 time trial on Wednesday.

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Paralympics 2012: The best photos – Nicholas Taylor of the United States plays a forehand in the quad doubles wheelchair tennis final on Wednesday.

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Paralympics 2012: The best photos – Britain's David Anthony, center, reacts to scoring a goal against the United States during a Pool A wheelchair rugby match on Wednesday.

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Paralympics 2012: The best photos – Kenny Allen of Great Britain reacts after losing the match against China in the semifinal of the men's team recurve on Wednesday.

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Paralympics 2012: The best photos – Will Groulx, center, of the United States gets upended by Britain's Aaron Phipps, left, during the rugby match on Wednesday.

Paralympics 2012: The best photos – Tanto Campbell of Jamaica competes in the men's discus throw F54/55/56 final on Wednesday.

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Paralympics 2012: The best photos – Jenny McLoughlin of Great Britain reacts after the women's 4x100-meter relay - T35/T38 in which her team won the bronze medal Wednesday.

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Paralympics 2012: The best photos – Brazilian Terezinha Guilhermina loses her guide Guilherme Soares de Santana after he fell in the Women's 400-meter T12 final at the 2012 London Paralympic Games on Tuesday, September 4.

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Paralympics 2012: The best photos – British racer David Weir celebrates winning the Men's 1500-meter T54 final on Tuesday.

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Paralympics 2012: The best photos – Chinese Daoliang Hu, left, on his way to winning gold against Ukrainian Anton Datsko on Tuesday during the men's final of wheelchair fencing.

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Paralympics 2012: The best photos – Katharina Kruger of Germany plays a shot while competing with Sabine Ellerbrock against Jordanne Whiley and Lucy Shuker of Great Britain during the women's doubles wheelchair tennis quarterfinal match on Tuesday.

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Paralympics 2012: The best photos – Brazil's Yohansson Nascimento celebrates finishing second in the men's 400-meter T46 final on Tuesday.

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Paralympics 2012: The best photos – Venezuela's Williams Barreto competes in the men's long jump - F20 final on Tuesday.

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Paralympics 2012: The best photos – Walid Ktila of Tunisia crosses the line to win gold on Tuesday in the men's 200-meter - T34 final.

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Paralympics 2012: The best photos – Daniel Silva of Brazil and guide Heitor de Oliveira Sales win silver in the men's 200-meter - T11 final on Tuesday.

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Paralympics 2012: The best photos – Sophie Wells, Lee Pearson, Deborah Criddle and Sophie Christiansen of Great Britain wear their team gold medals for the equestrian event on Tuesday.

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Paralympics 2012: The best photos – China's Wang Yanzhang competes in the men's shot put F34 final on Tuesday.

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Paralympics 2012: The best photos – Natalie Schneider of the United States reaches for the ball in the women's wheelchair basketball quarterfinals against Canada on Tuesday.

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Paralympics 2012: The best photos – Venezuela's Jesus Aguilar swerves off the track as he approaches the finish line in the men's 800-meter T53 heats.

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Paralympics 2012: The best photos – Turkey's Ramazan Kunduz uses the side wall for guidance during the men's team football 5-a-side B1 preliminary match Tuesday.

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Paralympics 2012: The best photos – Ruslan Katyshev of Ukraine competes in the men's long jump F11 final Tuesday.

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Paralympics 2012: The best photos – Brazil's Flavio Reitz competes in the men's high jump F42 final on Monday, September 3.

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Paralympics 2012: The best photos – Russia's Sergey Malyshev shoots during the mixed 25-meter pistol final on Monday.

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Paralympics 2012: The best photos – Mickey Bushell of Great Britain crosses the line to win gold in the men's 100-meter final.

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Paralympics 2012: The best photos – Matt Stutzman of the United States competes in men's individual compound archery.

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Paralympics 2012: The best photos – Cuba's Omara Durand celebrates after taking the gold medal in the women's 400-meter final.

Paralympics 2012: The best photos – Filomeno Soares of East Timor competes in the men's 400-meter - T38 heats at Olympic Stadium. The winner, Venezuela's Omar Monterola, lies on the floor after crossing the finish line.

Paralympics 2012: The best photos – Gordon Reid of Great Britain prepares to serve during the men's singles wheelchair tennis round 64 match against Takuya Miki of Japan in London on Saturday, September 1.

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Paralympics 2012: The best photos – Brazil's Terezinha Guilhermina, left, prepares with her coach at the start of the women's 200-meter T11 race.

Paralympics 2012: The best photos – Hannah Cockroft of Great Britain competes in the women's 100 meters on day 2 of the London 2012 Paralympic Games at Olympic Stadium on Friday, August 31.

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Paralympics 2012: The best photos – Lahouari Bahlaz of Algeria competes in the men's club throw on Friday.

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Paralympics 2012: The best photos – Sophie Pascoe of New Zealand in action during the women's 50-meter freestyle.

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Paralympics 2012: The best photos – Julie Rogers, from left, Jessica Frezza, Martine Wright and Andrea Green of Great Britain react to a point during the opening game of the womens sitting volleyball tournament against Ukraine.

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Paralympics 2012: The best photos – A spectator gets into the athletics action on Friday.

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Paralympics 2012: The best photos – A competitor walks across the athletics track.

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Paralympics 2012: The best photos – James Crisp of Great Britain swims in the men's 100-meter backstroke.

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Paralympics 2012: The best photos – Mark Colbourne of Great Britain competes in the men's individual cycling event.

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Paralympics 2012: The best photos – Ukraine's Alla Lysenko (second in row) prepares to take part in the women single sculls heat on Friday.

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Paralympics 2012: The best photos – Great Britain's Ade Oregbemi takes a tumble in the preliminary men's wheelchair basketball match, which Germany won 77-72, on Thursday, August 30.

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Paralympics 2012: The best photos – The Great Britain team leaves the court losing to China during the women's goalball match between China and Great Britain.

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paralympics fri 07 – LONDON, ENGLAND - AUGUST 31: General view of Greenwich Park equestrian venue as competitors take part the Dressage event on day 2 of the London 2012 Paralympic Games at Greenwich Park on August 31, 2012 in London, England. (Photo by Chris Jackson/Getty Images)

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Paralympics 2012: The best photos – China's Zheng Tao celebrates breaking the world record after winning the men's 100-meter backstroke swimming event.

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Paralympics 2012: The best photos – Gold medalist Sarah Storey of Great Britain poses on the podium during the victory ceremony for women's cycling.

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Paralympics 2012: The best photos – The Australian women's wheelchair basketball team huddles and celebrates their victory during their preliminary basketball game against Brazil.

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Paralympics 2012: The best photos – Fans watch the preliminary wheelchair men's basketball match between Great Britain and Germany, which Germany won 77-72.

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Paralympics 2012: The best photos – The United States' Jessica Long, left, and Ukraine's Kateryna Istomina compete in the women's 100-meter butterfly.

Paralympics 2012: The best photos – The Netherlands' Inge Huitzing passes the ball as Britain's Laurie Williams, left, and Caroline Maclean defend during the preliminary women's group A wheelchair basketball match.

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Paralympics 2012: The best photos – Prince William and his wife, Catherine, applaud as they watch British cyclist Sarah Storey break a world record in her C5 individual pursuit heat.

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Paralympics 2012: The best photos – Natalie du Toit of South Africa competes in the women's 100-meter butterfly heat.

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Paralympics 2012: The best photos – A volunteer moves the prosthetic leg of Sven Decaesstecker of Belgium during the men's SM10 200-meter individual medley swimming heat.

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Paralympics 2012: The best photos – Natalie Smith of Australia competes in the Women's R2-10-meter air rifle standing SH1 finals.

Paralympics 2012: The best photos – Torchbearers exchange the Paralympic flame outside Westminster Abbey in London on Wednesday, August 29.

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Paralympics 2012: The best photos – A young boy waits for the arrival of the Paralympic torch in Trafalgar Square ahead of the start of the Games.

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Paralympics 2012: The best photos – The cauldron is lit as the four Paralympic flames, which were lit on the UK's highest peaks, are united at Stoke Mandeville Hospital during the torch relay on Tuesday, August 28, in Aylesbury, England.

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Paralympics 2012: The best photos – Members of Team GB Paralympic look on as they are welcomed by dancers during a ceremony at the Paralympic Village.

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Paralympics 2012: The best photos – Paralympic athletes from Switzerland push their wheelchairs ahead of the London 2012 Paralympic Games.

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Photos:Paralympics 2012: The best photos

Paralympics 2012: The best photos – Dancers perform during a welcome ceremony at the Paralympic Village.

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Photos:Paralympics 2012: The best photos

Paralympics 2012: The best photos – A general view shows the Olympic Velodrome.

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Photos:Paralympics 2012: The best photos

Paralympics 2012: The best photos – Members of Team GB Paralympic are cheered on by dancers.

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Photos:Paralympics 2012: The best photos

Paralympics 2012: The best photos – Flags fly in the Olympic Park ahead of the London 2012 Paralympic Games.

"Classification exists in the Olympics as well," explains Dr. David Howe, a former Canadian Paralympic middle-distance runner and academic at Loughborough University.

"Men and women don't compete together, and in boxing and judo it's based on weight, but in the Paralympics it gets broken down much more finely.

"So take people with visual impairments. You have the B3 class where someone has 10% vision, B2 class with 5% vision and B1 no usable vision at all.

"It has a huge impact on how you can train. If you have no usable vision you need someone to train with you. If you have 10% they can, and they do, move around on their own. They can train. That gives them a huge advantage."

Talent, not disability

In recent years the IPC has complicated things further by trying to slim down the number of medals and disciplines and look beyond the disability as the defining factor in classification.

Instead, it says, look to the potential of the athlete.

"During classification ... athletes are assessed for their ability to perform in a particular event," the IPC explains.

"'Ability' in this case refers to an athlete's functional potential and is not an assessment of their disability: this is a complete reversal of the old systems that were clinical and medical in origin and often intrusive."

This is why Oscar Pistorius, the South African double amputee "Blade Runner" who made history by becoming the first track and field Paralympian to compete in the able-bodied Olympics -- can line up against runners with only one prosthetic leg.

Photos:Rwanda's sitting volleyball team

Photos:Rwanda's sitting volleyball team

Sit down, stand up – It has been a long road to the London 2012 Paralympics for the Rwandan men's sitting volleyball team, which is the best in Africa.

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Photos:Rwanda's sitting volleyball team

Sit down, stand up – Team captain Dominique Bizimana told CNN: "I think we are superstars. For us disability is nothing. We are able. We are making sure we tell people disability is nothing. It is not inability."

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Photos:Rwanda's sitting volleyball team

Tools of the trade – Most of the players are amputees from the country's 1994 genocide.

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Photos:Rwanda's sitting volleyball team

War child – As many as one million people were killed when a civil war between the majority Hutus and minority Tutsis broke out.

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Photos:Rwanda's sitting volleyball team

Training day – Hundreds of thousands of people were left maimed, but sport has provided an outlet for many and helped reconciliation between the two communities. Both Hutus and Tutsis are in the volleyball team.

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Photos:Rwanda's sitting volleyball team

Match point – The game itself is fast paced and, according to the team's Dutch coach, technically more demanding than able-bodied volleyball.

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Photos:Rwanda's sitting volleyball team

Brothers in arms – The team's training facilities in the capital Kigali are basic. The players hope to spring a surprise or two, but lost their opening game to Iran, one of the favorites for gold.

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Photos:Rwanda's sitting volleyball team

Challenges ahead – The Rwandans will also face Brazil, China and Bosnia-Herzegovina in Pool B.

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Photos:Paralympics Opening Ceremony

Photos:Paralympics Opening Ceremony

Paralympics opening ceremony – Paralympian Margaret Maughan lights the Paralympic cauldron during the opening ceremony of the London 2012 Paralympics on Wednesday, August 29.

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Photos:Paralympics Opening Ceremony

Paralympics opening ceremony – The Paralympic flag is carried by members of the Great Britain wheelchair basketball team.

In the pool on Thursday, China's Zheng Tao won gold in the 100 meters backstroke, destroying the field despite not having any arms.

According to Howe, back when he was competing, the procedure to determine classification was very different and also highly intrusive.

"When you compete for the first time they make sure you are not fiddling the system," he says.

"You have a medical doctor -- I have mild cerebral palsy -- physio and a technical expert. Now they have the ability to examine classification after competition. They used to run them before major competitions and force athletes through them. I refused until after the contest because it can be quite exhausting."

The move towards streamlining the classifications and having less medals to give out also has it drawbacks.

"Swimming is a bit of fiddle," says Howe when asked about the Arlen case. "I was there to see the British lad Jonathan Fox win gold, the roar was amazing.

"But the thing is when they came out (of the pool) he looked the most able. He was the only one not using a stick or wheelchair.

"There's a water-based test and a land-based test, and an element that you are on a performance curve -- and that discourages training. You want to be on the right side of the thin line from the next category. Otherwise you'll struggle."

The politics of classification

But, of course, competitive sport is competitive sport -- and rival teams regularly refer athletes for reclassification if they feel they have an unfair advantage.

The Paralympic movement has also been stung by several high-profile scandals. The Spanish Paralympic basketball team was stripped of their gold medals at the 2000 Sydney Games after it emerged that some of the players weren't properly tested and were not intellectually disabled. The controversy saw the entire category of intellectually disabled sport withdrawn from the next two Olympics. It is only now, in London, making a comeback.

Photos:Meet the African Paralympic stars

Photos:Meet the African Paralympic stars

Elliot Mujaji – Elliot Mujaji was a member of Zimbabwe's national athletics team and qualified to compete at the 1998 Commonwealth Games, when he suffered severe burns in an electrical accident. His right arm was amputated, and he remained in a coma for two months. He came back to athletics, and won the first ever Paralympic gold for his country.

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Photos:Meet the African Paralympic stars

Oscar Pistorius – South Africa's "Blade Runner" Oscar Pistorius made history at London 2012 by becoming the first double amputee to compete on the track and make an Olympic final. He is the favorite in the Paralympics 100 meters run.

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Photos:Meet the African Paralympic stars

Henry Wanyoike – In 1995, while training to become a professional runner, Henry Wanyoike became almost completely blind after suffering a stroke. He got back to competing, and became one of the fastest men on the planet. He holds two world records in 5,000 meters, 10,000 meters and the record time for marathon.

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Photos:Meet the African Paralympic stars

Achmat Hassiem – Achmat Hassiem lost his foot to a Great White shark when participating in a lifeguard training session in 2006. After an amazing recovery, he qualified for the 2008 Beijing Paralympics and has been competing ever since. Inset picture: Hassiem shows off a fragment of a shark's tooth that was stuck in his leg after he was attacked.

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Photos:Meet the African Paralympic stars

Natalie Du Toit – South African Natalie Du Toit lost her left leg when she was hit by a car as a young promising swimmer. She kept training and, besides winning five gold medals in Beijing Paralympics, she qualified for Beijing Olympics 10 km swimming race, finishing 16th. She recently announced London will be her last major competition.

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Photos:Meet the African Paralympic stars

Metwaly Mathana – The star of Egyptian powerlifting, Metwaly Mathana started the sport at the age of 5. According to his bio with the Egyptian Paralympic committee, he had to leave his village as there was not enough steel for him to keep lifting. He won three gold medals in three consecutive Games.

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Photos:Meet the African Paralympic stars

Somaya Bousaid – Tunisia's Somaya Bousaid won two gold medals in Beijing 2008 Games -- and became one of the most successful athletes from her country. She was born blind and competes in the category of visually-impaired athletes.

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Photos:Meet the African Paralympic stars

Roxy Burns – Cyclist Roxy Burns, a South African cerebral palsy sufferer, made her Paralympic debut in Beijing in 2008. As an 18-year-old, she finished sixth in the 500 meters track time trial. Her results have been improving since Beijing and she is one of the favorites for a medal.

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Photos:Meet the African Paralympic stars

Tesfalem Gebru Kebede – Tesfalem Gebru Kebede won a bronze medal in last year's world championship and is one of Ethiopia's top athletes. He lost his hand when his house was bombed during the Ethio-Eritrea war.

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Paralympics arrive in London – Disabled marathon runner Claire Lomas, center, lights the Olympic cauldron for the Paralympic Games in Trafalgar Square on August 24, 2012. The London 2012 Paralympic Games open on August 29 for 12 days.

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Paralympics arrive in London – Paralympian athlete Angela Hendra prepares to light the cauldron during the London 2012 Paralympic Games lighting ceremony at Stormont Government buildings in Belfast, Northern Ireland on August 25.

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Paralympics arrive in London – People watch a fireworks display on August 25 after a Paralympic cauldron was lit outside Northern Ireland's parliament in Belfast, the second of four in Britain's capital cities ahead of the 2012 Games.

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Paralympics arrive in London – Marieke Vervoort of Belgium's Paralympic team arrives by Eurostar at St Pancras International station in London on August 26.

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Paralympics arrive in London – Russian Paralympians arrive at Heathrow's Terminal Four on August 22 in London.

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Paralympics arrive in London – Performers dance during the New Zealand Flag Raising Ceremony at the Olympic Park on August 27 in London.

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Paralympics arrive in London – Prime Minister David Cameron meets members of the Great Britain Paralympics archery team during a visit to the Olympic village, ahead of the London 2012 Paralympic Games in the Olympic Park, on August 24.

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"There's a huge amount of politics in classification," agrees Howe.

"I was never asked as an athlete, 'Do you think the contest was fair?' For the athletes (like Arlen) it can be hell. When this does happen the athletes come together 'Band of Brothers' style."

Arlen returns

In the end that is exactly what happened to Victoria Arlen. After an outcry the IPC reviewed the evidence again and cleared her to compete in this weekend's 400 meters heats, one of the most anticipated events at the Games. But it is unlikely to be the last time the issue of classification hits the headlines.

"I've been involved since 1986 and it's always been an issue," says Howe.

"It's getting much better. But I worry that by bringing in less categories they (the IPC) are trying to be more media friendly. If it is fair, fine, but I am against that if that stops different impaired bodies being involved.

"We must not forget that, first and foremost, the Paralympics is about celebrating difference. It's not about ability versus disability."